Hydraulic surface grinding machine



March 21, 1939.

c." G. FLYGARE ET AL' HYDRAULIC SURFACE GRINDING MACHINE Filed Aug. 18, 1938 2 Sheets-Sheet 1 grwe/Mm EHRL G.FLVBH E ERBE'R FLEILVEN March 21, 1939. Q G, FLYGARE ETA 2,151,637

HYDRAULIC SURFACE GRINDING MACHINE Filed Aug. 18, 1938 2 Sheets-Sheet 2 v CFiHL BF'LYGHHE F E HERBERT FLSILVEN Mum Patented Mar. 21, 1939 UNITED STATES PATENT OFFICE 2,151,637 IIYDRAULIG SURFnCE GRINDING MACHINE I Carl G. Flygare and, Herbert A. Silven, Worcester, Masss assignbrs to Norton Company,

Worcester, Mass., a corporation of Massachusetts Application August 18; 1938, Serial No. 225,582

Claims. (01. 51-92) grinding spaced plane surfaces on a work piece.

Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly consists in the features of construction, combinations of elements, and arrangements of parts, as will be exemplified in the structure to be hereinafter described,

and the scope of the application of which will be indicated inthe following claims.

In the accompanying drawings, in which is shown one of various possible embodiments of the mechanical features of this invention,

Fig. 1 is a front elevation of the improved surface grinding machine having parts broken away and shown in section to'more clearly show the \operating mechanism;

Fig. 2 is a fragmentary diagrammatic view showing the hydraulic mechanism for moving the wheel slide transversely and also the hydraulical- 1y operated mechanism for moving the wheel slide vertically; and

Fig. 3 is a fragmentary sectional view taken approximately on the line 3-3 of Fig. 1, showing the control valve for controlling the admission to and exhaust of fluid from the hydraulic cylinder for positioning the grinding wheel.

Fig. 4 is a detail-of the mechanism for manually moving the wheel slide transversely.

A surface grinding machine has been' illustrated in the drawings having a base II) which supports a longitudinally reciprocable work table II. The table [I is supported on the usual v- 5 way and flat way (not shown) on the base It. A

V grinding wheel I5 is' rotatably mounted on a transversely movable wheel slide I6 which is supported bya dovetailed slideway onv a vertically 5 movable slide l1 carried by an upwardly extending portion I8 of the base Ill. The vertical slide II is arranged for manual adjustment to position the periphery of the grinding wheel l5 relative to the surface of a work piece which is mounted 65 on the table II so as to grind the surface to the required extent. This-mechanism may comprise a manually operable feed wheel 20 of the well known type such as that shown in the prior United States patent to Norton No. 1,108,779

dated August 25, 1914 and the patent to Flyvgare and Wood No. 2,022,542 dated November 26,

1935. Reference may be had to these patents for details of disclosure not found herein.

The manually operable feed wheel 20 is connected to rotate a gear 2i meshing with a gear 22. threaded aperture which meshes with or engages a feed screw 23. The gear 22 is rotatably supported by anti-friction bearings 2t and 25 which are in turn supported within a casing 26 and serve to hold the gear 22 against endwise movement. When the gear 22 is rotated by manual The gear 22 is formed with an internal rotation of the feed wheel 20, rotation of the threaded aperture within the gear'ZZ causes an endwise vertical movement of the feed screw 23 which serves in a manner to be hereinafter described to raise and lower the vertically movable slide i! so as to position the grinding wheel l5 vertically relative to the table i i.

A vertically arranged shaft 28 is slidably mounted within an aperture within the feed screw 23 and is slidably keyed within said aperture by means of a key 29-. The lower end of the rod or shaft 28 is connected by a stud 30 with the vertically movable slide II.

,Table reciprocating mechanism The table II is arranged so that it may be reciprocated by a power operated mechanism to 'pass the work piece beneath the operative face of the grinding wheel 15; In the preferred form, the reciprocating mechanism comprises a fluid pressure system comprising a cylinder 35 which .is fixedly mounted in the base I. A piston 36 is chamber 46 at the left-hand end of the'cylinder 35, or through a passage 41 into a cylinder chamber 48 at the right-hand end of the cylinder 35, so as to reciprocate the table l l in either direction as desired. For other details of the l'rv- 1 draul'ic mechanism forreciprocating the table,

control the normal reference may be had to the prior United States Patent N0. 2,022,542.

Reverse valve actuating mechanism A depending portion SI of the lever 58 is pro-' vided with a gear segment 52 which meshes with a gear segment 53 mounted on the outer end of a rock shaft, the inner end of which is connected through a gear to rotate the reversing valve. .It will be readily apparent from the foregoing disclosure that when the lever 58 is rocked in either direction, motion will be transmitted through the gear segments 5| and 52 to actuate the reversing valve. In order that the reversing valve may be shifted rapidly into a reverse position after the lever has moved toward a central position, a pivotal load and fire mechanism is provided. For details of disclosure of this mechanism, reference may be had to the prior United States Patent No. 2,022,542.

The lever 58 may be actuated manually or in the preferred form may be actuated in timed relation with the movement of the table I I by adjustable dogs 88 and 8| which are adjustably mounted in a T-slot 62 formed on the front of the table II. Assuming the table to be traveling in the direction of the arrow, as indicated, the table continues moving in this direction until the dog 88 strikes a projection on the reversing lever 58 and swings the reversing lever in a clockwise direction to shift the reversing valve into a reverse position to change the direction of flow of fluid under pressure to the cylinder 35.

Throttle value I In order that the normal speed of the table may be varied to give the desired relative speed between the operative face of the grinding wheel and the work piece, a throttle device is provided which comprises a throttle valve 85 located in the exhause side of the fluid pressure system so that the speed of the table I I is regulated by the exhaust of fluid from the cylinder 35. The throttle valve 85 is preferably provided in an integral part of the reverse valve mechanismand is actuated by a manually operable lever 88. By manipulation of the lever 88, the operator may vary the aperture of the throttle valve 85 and thereby speed of the table.

Transverse wheel feeding mechanism In grinding of plane surfaces on a surface grinding machine of the type in which the work supporting table reciprocates beneath the wheel I5, it is desirable to provide a feeding traversing mechanism to traverse the grinding wheel transversely at the end of a table stroke so as to present the wheel face to a different portion of the work on the next table stroke. It is desirable to provide such a mechanism with a power actuated device which operates automatically to index or traverse the grinding wheel transversely at either or both ends of the table stroke. As illustrated in the drawings, a fluid pressure cylinder I8 is mounted within the vertically movable slide IT.

A slidable piston II within the cylinder I8 is connected by a piston rod I2 to a bracket 13 which projects rearwardly from the wheel slide I6. A reversing valve I8 is provided to permit changing the direction of movement of the slide I8. E'he valve I8 is preferablypf the balanced piston I plane surface of a work piece.

in which fluid under'pressure fromfa pump- 15 is conveyed through a pipe 18 and a pipe 11 to a valve chamber I8, In the position illustrated in Fig. 2, fluid under pressure entering the valve chamber 18 passes through a passage 19 into a cylinder chamber 88 at the right-hand end of, the cylinder I8. During this movement, fluid is exhausted from a cylinder chamber 8I at the other end of the cylinder 18, through a passage 82, into a valve chamber 83, and out through a pipe 88 and a pipe 85 which'returns it to the reservoir 48 in the base I8. The pump I5 has been shown diagrammatically in Fig. 2 as a separate pump unit. This pump may be a separately operated independently motor driven pump or may be combined with fluid pressure pump 4| as a. tandem pump unit driven by a single electric motor.

The valve I4 is provided with a valve stem 86 and an actuating knob 81. When the knob 81 is moved toward the left (Fig. 2) to shift the reversing valve II into the reverse position, fluid under pressure passing through the pipe 11 into the valve chamber I8 passes through the passage 82 into the cylinder chamber 8I to cause the wheel slide I6 to move toward the right (Fig. 2).

During this movement, fluid exhausts from the cylinder chamber 88, through the passage I9, through a valve chamber 88, and out through the pipes 84 and 85 to the reservoir. By manually shifting the valve II by means of the manually operable knob 81, the wheel slide may be moved by fluid under pressure in either direction to pesition the grinding wheel I5 for grinding the If desired, the wheel slide It may be provided with a dog bar 88 and adjustable dogs 8| (Fig. 3), only one of which has been illustrated, which are arranged in the path of a projection 92 of a reversing lever which is arranged to shift the valve I4 automatically in timed relation with the transverse movement of the slide I8 so as t0 automatically reverse its direction of movement after it has traversed a predetermined extent in either direction. This mechanism has not been illustrated in detail in the present case since it is not considered a part of the present invention. For further details of construction of this automatic reversing mechanism for the valve I4, reference may be had to the above-mentioned prior United States Patent No. 2,022,542.

To attain one of the main objects of the invention, it is desirable to provide a rapid vertical positioning movement for the wheel I5. In grinding work pieces on a surface grinding machine of this type having spaced plane surfaces which are arranged at difl'erent horizontal levels, it is necessary to position the wheel I5 at different levels for grinding the spaced surfaces thereon. In the preferred form, it is desirable to provide an automatically actuated mechanism, such as a hydraulically operated mechanism comprising a cylinder I88 which is supported on the upper end of the feed screw 23. A piston I8Iis slidably mounted within the cylinder I88 and is fixedly connected to the upper end of the rod 28 which serves as a piston rod. When fluid under preswheel slide I6 and the grinding wheel I5 to a different position. The upward vertical movement of the piston IOI may be limited by means of an adjustable stopscrew'l04. During the upward movement of the piston IOI, fluid within a cylinder chamber I05 above the piston, III is exhausted through a pipe I06 in a manner to be hereinafter described. d

A control valve H is provided for controlling the admission and exhaust of fluid to and from the cylinder I00. The control valve H0 is preferably a piston type valve comprising a valve stem III having formed integrally therewith valve pistons ,II2, H3, H4, H and H6. The valve H0 is, shown in its downward position (Figs. 2 and 3) A roller H0 is rotatably supported by a stud/ H9 on the lower end of the valve stem III and is arranged to ride on a cam surface I26 which is fixedly supported on a bracket I2I pro- J'ecting from the wheel slide I6. A spring I22 which is supported in an aperture in the upper end of the valve piston and interposed between the bottom of the aperture and the valve head serves to maintain the roller I I8 in operative engagement with the cam I20.

When the wheel slide I6 is traversed trans- ,versely either, manually by a manually [operable mechanism, such as that shown in the prior United States Patent No. 2,022,542, or byfluid under pressure as disclosed above, the cam I- traverses with the slide and the roller I I0 following the cam serves to change the position of the valve so as tocontrol the admission of fluid to and from the cylinder I00. 'When the wheel slide I6 is moved so as to traversethe'cam I20 toward the right (Fig. 3), the roller II8 will ride up the inclined surface of the cam I20 onto a horizontally extending portion I23 to shift the valve 50 asto reverse the direction of flow of fluid.

Fluid under pressure passing through the pipe 16 enters a valve-chamber I25 between the valve pistons I I3 and I I4 and passes out through a port I26 into the pipe I06 'to apply fluid under pressure to the cylinder chamber I05 to move the piston IOI in a downward direction. During this movement, fluid within the cylinder chamber I03 exhausts through thepipe I02, a port I21, into a valve chamber I28, and passes out through a port I29 and exhauststhrpugh the pipe 05 into the reservoir 40. When the cam I 20 is traversed toward the right (Fig. 3) to cause the valve to move in an upward direction, the direction of flow of fluid to the cylinder I00 is reversed. In thisv position of the valve. fluid under pressure from the pipe 16 enters the valve chamber I25, and passes out through the port I21 and pipe I02 into the cylinder chamber I03 tocaus'e the piston IOI tomove in an upward direction. During the upward ovement of the piston IOI, fluid within the cylinder chamber I05 exhausts through p pe I06, the port I26, into a valve chamber I30, and passes out through a port I3I, into the pipe 05,

to return to the reservoir.

During the vertical positioning movement of the grinding wheel I5 and the transverse setting thereof to position the wheel for grinding in a second position on the work piece, it may be desirable in grinding certain types of work to cut off the fluid pressure traversing movement so that the wheel slide may be positioned manually for grinding the second portion on a work piece. During the normal operation of the machine, fluid under pressure passing through theplpe 16 also passes through a pipe I and a port I36 into a valvechamber I31 located between the valve pistons H5 and H6 and passes out through a port I36, into the pipe II which conveys flu d under pressure to the valve 14 which controls the transverse movement of the wheel slide I6.'

When the roller II8 rides onto the upper level portion I23 of the cam I20 to cause the grinding wheel I5 to rise vertically to facilitate reposition ing the wheel to grind a second portion on a work piece, the valve piston [I5 covers the port I 36 and thereby cuts off fluid from the pipel'I to prevent fluidpressure traverse of the wheel slide I6. By varying the shape of .the cam I20, the

grinding wheel slide I6 may be moved vertically to an inoperative position at one or more stations during its transverse movement in -accord-\ ance with the nature of the work being .ground.

In grinding spaced plane surfaces on a work piece which are in different horizontal planes, it

' may be desirable that the power transverse feed of the grinding wheel slide I6 be continuously operated and the vertical positioning mechanism be arranged independent of the transverse feedingmechanism so that it may be readily controlled. A by pass pipe I39 is connected between the pipes I6 and I1 and a shut-off valve I40 is provided in the pipe line I39. When the valve I40 is opened, fluid under pressure may pass continuously through the pipe 11 to the valve I4 'and independently of the control valve I I0 which controls the admission of fluid to the cylinder I00. In the open position of the valve I40, the wheel slide I6 may be indexed transversely and intermittently at the ends of the reciprocatory stroke of the work table II by a mechanism shown in detail in the prior United States Patent No. 2,022,542 to which reference may be'had for details of disclosure. During the transverse movement of the wheel slide, the roller II8 after travelling across the lower horizontal plane ofthe cam I 20 to grind one portion of the work piece,

travels up the rise in the cam to the second or 'tical slide II to posit on. the grinding wheel I5 for grinding a second portion of the work piece which is in a different horizontal plane from the flrst ground surface. The wheel slide I6 is continuously and intermittently indexed transversely to grind first the surface on the lower level wherein the valve is controlled by the surface I20 and the cam and then to grind the second surface where n the valve is controlled and positioned by the surface I23 on the cam.

This mechanism may also be utilized for grinding two spaced portions of a work piece which are interposed by acentral rib or projection located between the plane surfaces to be ground. By modifying the shape-of the cam I20, the valve IIO may be shifted as the grinding wheel approaches the rib or obstruction on the workpiece to ra se the grinding wheel to an uppermost or I6 may be positioned transversely by actuation of the valve I4 by means of the knob 81 to position the wheel in its initial relation with the work to grind a portion thereof. The wheel may be vof a shaft I44 of the shaft I44 carries a pinion or gear I45 which for the vertical slide .traverse of the wheel slide meshes with a rack bar I46 which is fixedly mounted on the slide I6 so that when the wheel I40 is rotated in either direction, a transverse movement will be transmitted to the slide I6.

vAfter the first portion of the work piece has been ground to the predetermined event, the wheel slide I 6 is moved transversely so that the cam I moves toward the right (Fig. 3) to shift the valve stem II I upwardly into the reverse position, which serves automatically to cut off fluid from the control valve I4 andprevent hydraulic I5 and at thesame time serves to admit fluid under pressure through the pipe I02 to raise the piston IOI vertically to raise the vertical slide I and the grinding wheel I5 to an inoperativeposition whilepositioning the wheel for-grinding a second portion of the work piece or while shifting to a second level for grinding a portion of the work piece to a different thickness.

It will thus be seen that there has been providedby this invention apparatus in which the various objects hereinabove set forth together with many thoroughly practical advantages are successfully achieved. As many possible embodiments may be made of the above invention and as many changes might be made in the embodiment above set forth, it is to be understood that all matter hereinbefore set forth or shown in the accompanying drawings-is to be interpreted as illustrative and not'in a limiting sense.

We claim:

1. In a surface. grinding machine, a rotatable grinding wheel, a transversely movable wheel slide, a verticallygmovable slide to support said transverse slide, a longitudinally reciprocable work supporting table, a separate power operated actuating mechanism for each of said slides and said table, and means including a cam on said wheel slide which actuates the power mechanism to position the grinding wheel vertically.

, 2. In a hydraulically operated surface grinding machine, a rotatable grinding wheel, a transversely movable wheel slide, a vertically movable slide to support said transverse slide, a longitudinally reciprocable work supporting table, a separate vertical slide motor being fluid motor for each of said slides and said table, a separate control valve for each of said motors, and a cam on said wheel slide which actuates the control valve for the vertical slide motor, vertically positioning the grinding wheel.

3. In a hydraulically operated surface grinding machine, a rotatable grinding wheel, a transversely movable wheel slide therefor, a vertically movable slide to support said transverse slide, a longitudinally reciprocable work supporting table, a separate fluid motor for each of said slides and said table, a separate control valve for each of said motors, the control valves for said vertical and said transverse slide motors being interlocked to prevent transverse slide motors being interlocked to prevent transverse movement of the wheel slide when the vertical valve is shifted to raise the grinding wheel. r

4. In a hydraulically operated surface grinding machine, a rotatable grinding wheel, a transversely movable wheel slide, a vertically movable slide to support said transverse slide, a longitudinally reciprocable work supporting table, a separate fluid motor for each of said slides and said table, a separate control each of said motors, said valve for controlling control valve for the mounted on the verti-v cal slide, a follower roller on said valve, and a cam on said wheel slide which engages said follower and serves to actuate the latter control valve when the wheel slide is traversed transversely automatically to position the grinding wheel for grinding spaced portions on a work piece in different horizontal planes.

5. In a hydraulically operated surface grinding machine, a transversely movable wheel slide, av

vertically movable slide to support said transverse slide, a longitudinally reciprocable work supporting table, a separate. fluid motor for said wheel slide and said table, a control valve for each of said motors, a. manually operable nut and screw feed mechanism to move said vertical slide to position the grinding wheel relative to the table, a. cylinder carried by said feed screw, a piston slidably mounted therein, a pistonrod slidably keyed within a central aperture in said feed screw, the upper end of said piston rod being connected to the piston and the lower end being connected to said vertical slide, a control valve to control the admission of fluid to said cylinder, and means including a cam on said transverse slide to actuate said valve to admit fluid under pressure to said latter cylinder to cause a vertical movement of said vertical slide relative to the nut and screw feeding mechanism to position the grinding wheel 

